Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755817Ab3DPLtz (ORCPT ); Tue, 16 Apr 2013 07:49:55 -0400 Received: from g4t0015.houston.hp.com ([15.201.24.18]:35737 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752899Ab3DPLty (ORCPT ); Tue, 16 Apr 2013 07:49:54 -0400 Message-ID: <516D3ADE.9060606@hp.com> Date: Tue, 16 Apr 2013 07:49:50 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.5) Gecko/20120601 Thunderbird/10.0.5 MIME-Version: 1.0 To: Ingo Molnar CC: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "Paul E. McKenney" , David Howells , Dave Jones , Clark Williams , Peter Zijlstra , linux-kernel@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, "Chandramouleeswaran, Aswin" , Davidlohr Bueso , "Norton, Scott J" , Rik van Riel Subject: Re: [PATCH 0/3 v2] mutex: Improve mutex performance by doing less atomic-ops & better spinning References: <1366036679-9702-1-git-send-email-Waiman.Long@hp.com> <20130416091259.GC9569@gmail.com> In-Reply-To: <20130416091259.GC9569@gmail.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1379 Lines: 29 On 04/16/2013 05:12 AM, Ingo Molnar wrote: > * Waiman Long wrote: > >> [...] >> >> Patches 2 improves the mutex spinning process by reducing contention among the >> spinners when competing for the mutex. This is done by using a MCS lock to put >> the spinners in a queue so that only the first spinner will try to acquire the >> mutex when it is available. This patch showed significant performance >> improvement of +30% on the AIM7 fserver and new_fserver workload. > Ok, that's really nice - and this approach has no arbitrary limits/tunings in it. > > Do you have a performance comparison to your first series (patches 1+2+3 IIRC) - > how does this new series with MCS locking compare to the best previous result from > that old series? Do we now achieve that level of performance? Compared with the old patch set, the new patches 1+2 have over 30% performance gain in high user load (1100-1500) in the fserver and new_fserver workloads. The old patches 1+2 or 1+3 only manages around 10% gain. In the intermediate range of 200-1000, the 2 sets are more comparable in performance gain. Regards, Longman -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/